ROME (AP) — A white truffle weighing more than three pounds, dug up in Tuscany by a truffle-sniffing dog, will be auctioned this week in Florence for charity.

Truffle hunter Cristiano Savini said Tuesday he was searching for truffles with his father last week in Palaia, about 25 miles from Pisa, when his dog, Rocco, started sniffing "like crazy."

With Rocco leashed to a tree to prevent him from digging too furiously, the Savinis carefully extracted a truffle they said weighed about 3.3 pounds, which they contended was a record.

The Guinness Book of World Records lists a 2.86-pound white truffle found in Croatia in 1999 as the biggest.

Cristiano's father, Luciano, said the truffle had been weighed at the traffic police station in the nearby town of San Miniato, which issued a certificate attesting to its weight. The station said the officer involved in the weighing was not immediately available for comment.

On Tuesday, Cristiano Savini brought the truffle to Rome to publicize the planned auction, to be held Saturday in a palace in Florence.

Truffles can fetch $5,500 a pound in Rome, although they usually weigh from 1 to 2.8 ounces. Slivers of truffles, with their strong aroma, are prized in Italy to flavor pasta sauces and rice dishes.

Proceeds from the auction will go to an Italian organization that helps sufferers of genetic diseases, a group that helps street children in London and Catholic charities in Macau.